Why can't yn Smart Campus verify the code?

The mobile phone is in arrears, the mobile phone card is in poor contact or the positioning signal is poor.

Maybe the SMS is full. This is because the short message storage capacity of mobile phones is also limited. If the user doesn't clean up the received SMS in time, resulting in too much information on the mobile phone, there will be cases where the subsequent SMS can't be received. It is recommended to delete the message and try again.

If the user does not turn on the phone for a long time or is in a place with poor signal, the arrival of information will be delayed, and generally the verification code will have a valid time. Failure to receive the message for a long time will also lead to the expiration of the message.